Typewriting machine



May 14, 1929. w. A. DoBsoN TYPEWRITING MACHINE Filed oct. 25, 1925 Patented May 14, 1929.

UNTED STATES PATENT OFFC..

WILLIAM A. DOBSON, OF BRIDGEPORT, CONNECTICUT, ASSGNOR TO UNDERWl-) ELLIOTT FISHER COMPANY, 0F NEW YGRK, N. Y., A GORPORATON 0F DELAWARE.

rvrnwnrrrne MACHINE.

Application lecl October 23, 1925. Serial No. 64,314.

This invention relates to the tension adjustinent oit' the returning springs lor the tey-levers of typewriting machines, and

.more particularly to Ineans lier locking the, l

swinging type-bars 13 when the `keys are deadj usting devices.

clince the keys of the machine are all 'l'ulcruined on a coininon shaft, and since sonic of the keys are longer than the others, the touch et seine et the keys is lighter than that oli others. lne of the 'features of this invention relates, therefore, to ineans Wheren by the inovcinent arising from this and other sources is overcome, and the touch ofall the keys is niadeuniliorin. There is provided a series et individual springs compressed between a tired plate under the keys and the keys themselves, the springs having individual adjusting ineans. Each spring is borne by a stud screwed into the plate, the springs and screws being staggered or arranged in cchelon to correspond with the arrangement oli the keys in rovvs and in a inanner to iinprove the leverage ot the keys.

AAnother ,feature oli this invention relates to means 'lorloehii'xg the studs tor the springs. lilor sinlultanieensly locking all the studs, there is provided a loch-plate Wide and long enougjh to take in all tl e studs, the studs being j novided with l'lattencd shanlrs into obn long holes in said j ilate.` The studs are .individually adjusted, ainl then the lock-plate is placed over the heads of the screws and is seciiu'ed to the fixed plate.

@ther features and advantages will hereinafter appear. l

.l'n the accompanying drawings,

lligiu'e l is a side vicW, in elevation, ot a type-action to which the invention may be advz ntagceusly applied. j

Vltiiiure 2 .is a plan view o'f Figure l.

"lt i,'ure Cil a Yfraginentary bottom view, showing` the loclepl ate and the stud-siiipporting plate, the latter being secured to the .traine oit the 1nachine.` Y

lligure l is a` cross-sectional vievv, :in ele vatioh, showingthe springs and adjusting means therefor.

rThis invention is illustrated as applied to the type-action of an Underwood portable typewriting machine. Said inachine has a series ot lreys ll), key-levers. ll liulcruined upon a conunon sha'it 12, and means for pressed. Said means inay include a series of rocking nieinbers lei; tulcruined upon a common shaft l5, and are operatively connected to the key-levers by means oit a pin lo and a slot l?. he rocking n'leinbers may be provided with upWarally-extending arins lfd, the ends thereof having holes 19 lier receiving the ends of links 20, which linlrs are pivotally `niounted at `2l upon lower extensions or short urine 22 ot the type-bars .l-5. The hey-.levers are returned to their normal. position, after each depression, by ine-ans o'l springs 23.

'ince the keys l0 are staggered as shown in Figure 2 and since the liulcruin-sha'lit l2 eill the key-levers is the saine Alor all the keys, it will be apparent that the longer key-levers will be easier to depress, thereby making the touch of the keys uneven, w i 1 i eh i s obj eetionable.

For thejiulrposc oit improving this condition, the positions oit the springs have been stagge-u'cd zmfolfding to the positions olf the lmys on the lmy-levers.` This will iin-` prove the uneven depref-ision olf` the keys some, but not enough to equalize the touch ol all the keys. lilach sprii'ig therefore provided with individual adjusting devices, which may include a series et" studs 24s tlireaded into a erossplate E25, the screws` being reduced in diameter at 2G for receiviug a flange or Washer 27. In order to stillen the cross-p`late 25, which 'is secured to the side traine 28 ci? the machine at the ends only, by means olf screws 29, it proposed to build it in the iforin of a channel having side 'walls 30, which may forni an :integral part oi' the cross-ililate 25.

The heads et the studs 2l may have the sides flattened at 3l in order to provide ineans whereby the studs may. be both screwed into the tapped holes andflocked against rotation after, adjusting the tension of the spring.

ATo this end, there is provided a plate 32 having elongated holes 33 of a width equal tothe width of the flattened portion of the studs, "The plate has one hole for each stud, and each hole is placed to correspond with the position of the studs in the crossplate 25. The plate 32 may be made wide enough to fit between the side walls 30 of the cross-plate, and may be secured in place by means ot'screws 34. The rear ends 35 of the key-levers ll may be provided with Vprojections 36, forming an integral part (thereot'y tor positioning the upper ends of the springs 28, said projections being in line with the studs 24.

Since the key-levers 1l are provided with an open slot 37 for engagement with the ,c scope of the invention, and portions of the improvements may be used withoutothers. Having thus describedr my invention, I

' claim l; In a portable typeWrit-ing machine, in combination, means for equalizing the touch of the key-levers includingv a series of compression springs arranged in staggered rows under the key-levers and studs having noncircular heads for adjnstably backing said springs, and unyielding, 'unitary means for lockingall of said studs against accidental rotation, including a plate Ahaving non-circular o pei'iings` withinl which saidv stud-heads are caged.

2. vIn a portable typewriting machine, i i

combination, means for equalizing the touch ofthe key-levers including a series olE compression springs -under thekey-levers, a

- `cross-bar secured to the sideframes of the machine and studs'screwed in said cross-bar,

and means for locking said studs against accidentalI4 rotation, said last-mentioned means including flattened portions on said studs, a plate having elongated holes therein for receivingall of said flattened portions, and instrumentalities for securing said plate to said cross-bar;`

3. In;atypewritingmachine having depressiblekey-levers fulcrumed at the rear of the machine upon a common shaft, the combination of meansforholding the key-levers 'being arranged 'in a 'plurality ol rows, a`

in their normal position, said means includ- 111g a Splngcunder each lever, the springs erossL-,framastuds screwed into said frame and serving as a. backing for said springs, said studs having downwardly-disposed heads of a non-circular cross-section, a plate having perforations for locking engagement with the heads of the studs, the perl'orations in the plate being placed to correspond with the position ot the studs in a manner to altord the entering olf all the heads into their corref'sponding per'l'oratimis in the plate to be caged therein, thereby pie venting the rotation oli' all the studs, and means for securing said plate against dis placement.

4l. In a portable typewriting machinel having depressible hey-levers and staggered Vkeys therefor, said ker-levers being parallel to each other and all being 'l'ulerumed upon a common shaflft at the rear ot the machine, the combination otl means tor equalixing the effort required to depresse the keys, said means including a series of springs under the key-levers and staggered to correspoiul to the staggered position of the keys, lattened studs in line with the springs l'or regulating the tension ot said springs, and means for simultaneously locking all the studs against rotation, said last-mentioned means including a thin, light locking plate having perforations arranged in staggered relation corresponding to the stud tormation for engagement with flattened portions ot said studs, so that the locking plate may be, simultaneousl7 passed over all the studs, and devices for locking the locking plate against displacement.

5. In a typenf'riting machine having depressible key-levers, the combination ol a U-shaped channel-plate extending under said levers between the sides ot said machine, said channel-plate having its side members turned down and being arranged with threaded holes through its web or top portion, one oi said holes being positioned under each ol said levers, studs threaded into each olf said holes, a spring supported on the upper end ot each stud tor pressing against a key-lever directly above it', a thin locking plate having a width wherebyv to permit it to lit snugly and eompactly between the side members ot such channelplate, and means for fastening said locking plate to said channelfplate, said locking plate having a plurality o't,i irregus larly-shapcd holes each arranged lor registering with one of said studs, the lowerend of each ol. said studs being shaped or flattened to all'ord a 1n ans `toi' turning said stud in said channel-plate to adjust the spring-pressure on the lmy-lever above, it, said lower ilattened end being Afurther arranged to engage snugly in the hole ot said locking plate below it to prevent accidental rotation oit said stud.

6. In a typewriting machine, in combination, a series of key-levers, a coil-restoring llt) weirg for each lever, a erossher having a selles ol studs threaded thelein, each stud having :m upper reduced pol-tion and a lower flattened portion integral. therewith, a bushing `inmlmted on Seid reduced poi-tion. :for support-ling the restorl'xg spring so that Upon rotation of said studs the springtension for each key-lever may be individually udjueted, and menne for locking the Studg against eeedental. rotation, said means i11- eluding e plete Secured to the cross-bar and having elongated holes therein to receive the lower flattened Stud-portions.

` lWILLIAM A. DOBSON. 

